<html>
<head><meta charset="utf-8"><title>log codegen regression · t-compiler · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/index.html">t-compiler</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/log.20codegen.20regression.html">log codegen regression</a></h3>

<hr>

<base href="https://rust-lang.zulipchat.com">

<head><link href="https://rust-lang.github.io/zulip_archive/style.css" rel="stylesheet"></head>

<a name="181148697"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/log%20codegen%20regression/near/181148697" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Steven Fackler <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/log.20codegen.20regression.html#181148697">(Nov 19 2019 at 20:00)</a>:</h4>
<p>Does anyone have any intuition as to what would have caused this? <a href="https://github.com/rust-lang/log/issues/365" target="_blank" title="https://github.com/rust-lang/log/issues/365">https://github.com/rust-lang/log/issues/365</a></p>



<a name="181149298"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/log%20codegen%20regression/near/181149298" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> mati865 <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/log.20codegen.20regression.html#181149298">(Nov 19 2019 at 20:08)</a>:</h4>
<p>Any clue when it started?</p>



<a name="181149354"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/log%20codegen%20regression/near/181149354" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Steven Fackler <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/log.20codegen.20regression.html#181149354">(Nov 19 2019 at 20:08)</a>:</h4>
<p>Not yet - I just noticed it a couple minutes ago. I'm going to try to get a minimal repro on godbolt and run back through their verisons</p>



<a name="181150018"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/log%20codegen%20regression/near/181150018" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Steven Fackler <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/log.20codegen.20regression.html#181150018">(Nov 19 2019 at 20:16)</a>:</h4>
<p>it looks like the existence of the fmt::Arguments argument breaks the optimization: <a href="https://rust.godbolt.org/z/ytgGyX" target="_blank" title="https://rust.godbolt.org/z/ytgGyX">https://rust.godbolt.org/z/ytgGyX</a></p>



<a name="181150037"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/log%20codegen%20regression/near/181150037" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Steven Fackler <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/log.20codegen.20regression.html#181150037">(Nov 19 2019 at 20:16)</a>:</h4>
<p>it does the right thing with that argument commented out, but the wrong thing when its present</p>



<a name="181150177"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/log%20codegen%20regression/near/181150177" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Steven Fackler <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/log.20codegen.20regression.html#181150177">(Nov 19 2019 at 20:18)</a>:</h4>
<p>oh - it's not assembling the tuple, its assembling the Arguments</p>



<a name="181150329"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/131828-t-compiler/topic/log%20codegen%20regression/near/181150329" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Steven Fackler <a href="https://rust-lang.github.io/zulip_archive/stream/131828-t-compiler/topic/log.20codegen.20regression.html#181150329">(Nov 19 2019 at 20:20)</a>:</h4>
<p>never mind me!</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
</html>